The present invention relates to a method enabling the simultaneous manufacture of two continuous streams of cigarettes.
U.S. Pat. No. 4,336,812 filed by the present Applicant relates to a manufacturing machine designed to enable the simultaneous manufacture of two continuous cigarette rods starting from a single strip of paper cut longitudinally into two essentially identical strips. By means of respective conveyor belts arranged side by side and driven by a single drive roller, the said two strips are fed along a top, where the said rods are made, and through a loading station where each strip is loaded with a respective stream of shredded tobacco.
One of the major operational drawbacks on the abovementioned machine lies in the use of the said single drive roller which presupposes the same dynamic behaviour on both conveyor belts. In actual fact, however, this is not so, owing to the fact that two conveyor belts are never exactly the same. It follows, therefore, that, when two theoretically identical belts are set up along identical routes and round a single drive roller, the speed of one may differ from that of the other, especially after a given operating time.
As, on the abovementioned machine, the two strips for making the two rods are formed from the same strip of paper, any difference in travelling speed could result in at least one of the strips being torn if the said difference is not rectified immediately.